1. Field of the Invention
The present invention relates to a pen housing that can be adjusted to accommodate commercially available ink cartridges of various sizes.
2. Related Art
A typical pen has a housing that holds a cartridge, which commonly comprises an ink reservoir and a writing mechanism to which the ink is delivered. The housing holds the cartridge in the correct position so that a user may write with the pen. The housing may be adapted for a single-use cartridge, or it may accommodate replacement cartridges.
A cartridge typically has a writing tip end and a butt end. In prior art pens the housing typically has two pieces that are detachably held together, such as by threads. Usually a spring or other biasing element is used to bias the writing tip end of the cartridge out of the pen housing. The spring or other biasing element may be attached at either the writing tip end or the butt end of the cartridge. The two pieces of the housing are detached from each other to remove and replace the cartridge.
While there are a wide variety of replacement cartridges available on the market, prior art pens are designed to accept only cartridges of a specific size. As a result, the user cannot use different brands or sizes of replacement cartridges. Therefore, there is a need in the art for a pen housing that can easily adjust to accommodate cartridges with different lengths, different thicknesses or different diameters.